// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_BASE_ATOMICOPS_INTERNALS_STD_H_
#define V8_BASE_ATOMICOPS_INTERNALS_STD_H_

#include <atomic>

#include "src/base/build_config.h"
#include "src/base/macros.h"

namespace v8 {
namespace base {

    namespace helper {
        template <typename T>
        volatile std::atomic<T>* to_std_atomic(volatile T* ptr)
        {
            return reinterpret_cast<volatile std::atomic<T>*>(ptr);
        }
        template <typename T>
        volatile const std::atomic<T>* to_std_atomic_const(volatile const T* ptr)
        {
            return reinterpret_cast<volatile const std::atomic<T>*>(ptr);
        }
    } // namespace helper

    inline void SeqCst_MemoryFence()
    {
        std::atomic_thread_fence(std::memory_order_seq_cst);
    }

    inline Atomic16 Relaxed_CompareAndSwap(volatile Atomic16* ptr,
        Atomic16 old_value, Atomic16 new_value)
    {
        std::atomic_compare_exchange_strong_explicit(
            helper::to_std_atomic(ptr), &old_value, new_value,
            std::memory_order_relaxed, std::memory_order_relaxed);
        return old_value;
    }

    inline Atomic32 Relaxed_CompareAndSwap(volatile Atomic32* ptr,
        Atomic32 old_value, Atomic32 new_value)
    {
        std::atomic_compare_exchange_strong_explicit(
            helper::to_std_atomic(ptr), &old_value, new_value,
            std::memory_order_relaxed, std::memory_order_relaxed);
        return old_value;
    }

    inline Atomic32 Relaxed_AtomicExchange(volatile Atomic32* ptr,
        Atomic32 new_value)
    {
        return std::atomic_exchange_explicit(helper::to_std_atomic(ptr), new_value,
            std::memory_order_relaxed);
    }

    inline Atomic32 Relaxed_AtomicIncrement(volatile Atomic32* ptr,
        Atomic32 increment)
    {
        return increment + std::atomic_fetch_add_explicit(helper::to_std_atomic(ptr), increment, std::memory_order_relaxed);
    }

    inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
        Atomic32 increment)
    {
        return increment + std::atomic_fetch_add_explicit(helper::to_std_atomic(ptr), increment, std::memory_order_seq_cst);
    }

    inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
        Atomic32 old_value, Atomic32 new_value)
    {
        atomic_compare_exchange_strong_explicit(
            helper::to_std_atomic(ptr), &old_value, new_value,
            std::memory_order_acquire, std::memory_order_acquire);
        return old_value;
    }

    inline Atomic8 Release_CompareAndSwap(volatile Atomic8* ptr, Atomic8 old_value,
        Atomic8 new_value)
    {
        bool result = atomic_compare_exchange_strong_explicit(
            helper::to_std_atomic(ptr), &old_value, new_value,
            std::memory_order_release, std::memory_order_relaxed);
        USE(result); // Make gcc compiler happy.
        return old_value;
    }

    inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
        Atomic32 old_value, Atomic32 new_value)
    {
        atomic_compare_exchange_strong_explicit(
            helper::to_std_atomic(ptr), &old_value, new_value,
            std::memory_order_release, std::memory_order_relaxed);
        return old_value;
    }

    inline void Relaxed_Store(volatile Atomic8* ptr, Atomic8 value)
    {
        std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
            std::memory_order_relaxed);
    }

    inline void Relaxed_Store(volatile Atomic16* ptr, Atomic16 value)
    {
        std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
            std::memory_order_relaxed);
    }

    inline void Relaxed_Store(volatile Atomic32* ptr, Atomic32 value)
    {
        std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
            std::memory_order_relaxed);
    }

    inline void Release_Store(volatile Atomic32* ptr, Atomic32 value)
    {
        std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
            std::memory_order_release);
    }

    inline Atomic8 Relaxed_Load(volatile const Atomic8* ptr)
    {
        return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
            std::memory_order_relaxed);
    }

    inline Atomic16 Relaxed_Load(volatile const Atomic16* ptr)
    {
        return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
            std::memory_order_relaxed);
    }

    inline Atomic32 Relaxed_Load(volatile const Atomic32* ptr)
    {
        return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
            std::memory_order_relaxed);
    }

    inline Atomic32 Acquire_Load(volatile const Atomic32* ptr)
    {
        return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
            std::memory_order_acquire);
    }

#if defined(V8_HOST_ARCH_64_BIT)

    inline Atomic64 Relaxed_CompareAndSwap(volatile Atomic64* ptr,
        Atomic64 old_value, Atomic64 new_value)
    {
        std::atomic_compare_exchange_strong_explicit(
            helper::to_std_atomic(ptr), &old_value, new_value,
            std::memory_order_relaxed, std::memory_order_relaxed);
        return old_value;
    }

    inline Atomic64 Relaxed_AtomicExchange(volatile Atomic64* ptr,
        Atomic64 new_value)
    {
        return std::atomic_exchange_explicit(helper::to_std_atomic(ptr), new_value,
            std::memory_order_relaxed);
    }

    inline Atomic64 Relaxed_AtomicIncrement(volatile Atomic64* ptr,
        Atomic64 increment)
    {
        return increment + std::atomic_fetch_add_explicit(helper::to_std_atomic(ptr), increment, std::memory_order_relaxed);
    }

    inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr,
        Atomic64 increment)
    {
        return increment + std::atomic_fetch_add_explicit(helper::to_std_atomic(ptr), increment, std::memory_order_seq_cst);
    }

    inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
        Atomic64 old_value, Atomic64 new_value)
    {
        std::atomic_compare_exchange_strong_explicit(
            helper::to_std_atomic(ptr), &old_value, new_value,
            std::memory_order_acquire, std::memory_order_acquire);
        return old_value;
    }

    inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
        Atomic64 old_value, Atomic64 new_value)
    {
        std::atomic_compare_exchange_strong_explicit(
            helper::to_std_atomic(ptr), &old_value, new_value,
            std::memory_order_release, std::memory_order_relaxed);
        return old_value;
    }

    inline void Relaxed_Store(volatile Atomic64* ptr, Atomic64 value)
    {
        std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
            std::memory_order_relaxed);
    }

    inline void Release_Store(volatile Atomic64* ptr, Atomic64 value)
    {
        std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
            std::memory_order_release);
    }

    inline Atomic64 Relaxed_Load(volatile const Atomic64* ptr)
    {
        return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
            std::memory_order_relaxed);
    }

    inline Atomic64 Acquire_Load(volatile const Atomic64* ptr)
    {
        return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
            std::memory_order_acquire);
    }

#endif // defined(V8_HOST_ARCH_64_BIT)
} // namespace base
} // namespace v8

#endif // V8_BASE_ATOMICOPS_INTERNALS_STD_H_
